Search results for "Efficient energy use"
showing 10 items of 282 documents
On the Energy Efficiency of Dual Prime Mover Pump-Controlled Hydraulic Cylinders
2019
Abstract This paper concerns the energy efficiency of a special class of pump-controlled hydraulic cylinders utilizing two prime movers. The performance of such circuits has been studied previously motivated by their capability of providing an actuator stiffness similar to that of servo valve-controlled systems. This characteristic may improve performance and robustness in applications requiring feedback control. In this paper, the presence of losses similar to that of fluid throttling, in the sense that they occur even in the absence of component inefficiencies, are demonstrated for such circuits and shown to degrade the overall energy efficiency of the system. The conditions under which s…
EECDC-MAC: An energy efficient cooperative duty cycle MAC protocol
2012
In this paper, we propose a novel energy efficient cooperative duty cycle MAC (EECDC-MAC) protocol in which sensor nodes use fixed wakeup rendezvous scheduling to exchange messages and a cooperative transmission mechanism to avoid overuse of nodes with lower residual energy. Numerical results demonstrate that the EECDC-MAC protocol can prolong the entire network longevity efficiently in comparison with an existing cooperative duty cycle MAC protocol, CDC-MAC, and another popular duty cycle MAC protocol, prediction wakeup MAC (PW-MAC) protocol.
Measure the Embodied Energy in Building Materials: An Eco-Sustainable Approach for Construction
2019
This paper highlights how the use of materials and building components often implicates the growth of embodied energy necessary to their construction, which is not always adequately compensated by a decrease of operational energy because incorporated energy can be almost half of the total energy used in a building’s life cycle and, sometimes, it even exceeds operational energy. The paper highlights how searching only for “operational” energy efficiency does not sufficiently guarantee environmental sustainability of the intervention. The intervention is heavily influenced by embodied energy whose knowledge must drive, since the beginning, the decision-making process towards more sustainable …
Smart Grid Security: A new Approach to Detect Intruders in a Smart Grid Neighborhood Area Network
2016
International audience; In this paper, we propose an efficient and lightweight attack detection mechanism for a smart grid Neighborhood Area Network (NAN) that combine between distributed and centralized intrusion detection. A NAN includes the customers' appliances, smart meters and collectors. The smart meters measure the power consumption of each appliance and the collectors aggregate the measures and forward them to the control center for analysis. Intrusion Detection System (IDS) agents, proposed in our framework, run in a distributed fashion at smart meters level and in a centralized fashion at collector and control center nodes. A combination between a rule-based detection and a learn…
Test of the European Joint Research Centre performance model for c-Si PV modules
2012
The performance of ten c-Si PV modules is studied at different levels of illumination and module temperatures and is modeled in terms of relative efficiency with respect to Standard Testing Conditions (STC). A recently proposed model is tested in Nordic conditions for generic mono- and mc-Si devices with screen-printed cells as well as for some high-efficiency cell designs. Two of the modules are field aged. Averaged model coefficients are derived and compared to values found in the literature. Irradiance and module temperatures measured in 2011 are then used to estimate the expected annual energy yields. The measured yields equal the predicted ones within 1.6% (mean bias error −1.0%) which…
Independent Geometrical Control of Spin and Charge Resistances in Curved Spintronics
2019
Spintronic devices operating with pure spin currents represent a new paradigm in nanoelectronics, with higher energy efficiency and lower dissipation as compared to charge currents. This technology, however, will be viable only if the amount of spin current diffusing in a nanochannel can be tuned on demand while guaranteeing electrical compatibility with other device elements, to which it should be integrated in high-density three-dimensional architectures. Here, we address these two crucial milestones and demonstrate that pure spin currents can effectively propagate in metallic nanochannels with a three-dimensional curved geometry. Remarkably, the geometric design of the nanochannels can b…
Energy Harvesting Enabled Energy Efficient Cognitive Machine-to-Machine Communications
2020
Energy harvesting based cognitive machine-to-machine (EH-CM2M) communication has been introduced to overcome the problem of spectrum scarcity and limited battery capacity by enabling M2M transmitters (M2M-TXs) to harvest energy from ambient radio frequency signals, as well as to reuse the resource blocks (RBs) allocated to CUs in an opportunistic manner. However, the complex interference scenarios and the stringent QoS requirements pose new challenges on resource allocation optimization. In this chapter, we consider how to maximize the energy efficiency of M2M-TXs via the joint optimization of channel selection, peer discovery, power control, and time allocation.
Electric-Motion in Romania - Overview - Study on Machining Parameters of EV Charging Station Mechanical Components
2016
This paper presents some relevant aspects of charging infrastructure for electric vehicles in Romania. It evidences the charging station and fast charging stations designed and installed by the first Romanian company dedicated 100% to e-mobility, E-Motion Electric. Also, a study on machining (milling) parameters of some mechanical components of electric vehicle (EV) charging station is done and, finally, the regression model for these parameters is determined. This model would be further used for machining process optimization.
Systems-dynamic analysis of employment and inequality impacts of low-carbon investments
2016
Abstract This paper provides a macroeconomic framework to evaluate the social and economic consequences generated by a shift of investment to low-carbon options. We introduce into a standard growth framework a modified Lotka–Volterra model for wage and employment determination to address both the long-run dynamics of the economic system in terms of carbon emission and GDP growth and the short-term macroeconomic fluctuations in terms of unemployment and inequality. We use this framework to compare the results of different combinations of three strategies for carbon emissions reductions: improvement in energy efficiency, expansion of the renewable energy sector, and the direct reduction in ca…
Designing a multi-layer edge-computing platform for energy-efficient and delay-aware offloading in vehicular networks
2021
Abstract Vehicular networks are expected to support many time-critical services requiring huge amounts of computation resources with very low delay. However, such requirements may not be fully met by vehicle on-board devices due to their limited processing and storage capabilities. The solution provided by 5G is the application of the Multi-Access Edge Computing (MEC) paradigm, which represents a low-latency alternative to remote clouds. Accordingly, we envision a multi-layer job-offloading scheme based on three levels, i.e., the Vehicular Domain, the MEC Domain and Backhaul Network Domain. In such a view, jobs can be offloaded from the Vehicular Domain to the MEC Domain, and even further o…